AWD rear diff grinding

Post by **Jack Rock** » 15 May 2012, 01:44

Last spring I removed the prop shaft on my 98 V70R AWD due to a ticking sound. Last fall I put in a rebuild shaft and within a couple of weeks a growling, banging sound from the rear started. I removed the shaft again and the problem minimized but there was a slight grinding/growling from the rear at highway speed. It kind of sounds like a wheel bearing rrrrr but cyclical at 1 second intervals. Now the sound is getting worse and I'm experiencing some vibration as well. I noticed also that both rear axles have some play up and down at the differential as well.

Here's the question, I read a post here that says you can remove the rear axles to eliminate the differential from turning but it seems to me from this picture that you would need the axle nut to hold on the spindle, wouldn't you? If you do, I suppose I could dismantle the outer cv joint and leave the short splined shaft in the hub as a kind of 'bolt' to hold things together.

Post by **jimmy57** » 15 May 2012, 06:19

You are right. The wheel bearing unit in hub requires the outer cv housing and the nut on shaft to keep the two halves of wheel bearing compressed together. If you gut the outer CV's on both sides you'll be fine.

Not all wheel bearings are like this. The newer Volvos with that bolt on axle up front have prestressed bearings and the axle bolt onlky keeps axle in and does not compress the races together for hub bearing.

Post by **Jack Rock** » 15 May 2012, 22:25

Thanks for the confirmation, I wanted to be sure before I destroy my rear axles. Any tips on gutting the outer CV joints or will it be clear once the boots are off?

Post by **jimmy57** » 15 May 2012, 23:47

get boots off and then clean grease off the center of the knuckle where the shaft slides into it. You will then see a snap ring that you compress with needle nose pliers and the shaft will pull out. With shaft out you can rotate knuckle around until ball come out. Then move knuckle until all the balls come free.

Post by **Jack Rock** » 29 Jun 2012, 10:33

jimmy57, I'm trying to get this done today but I'm stuck at the snap ring. I cut the boot off and I'm sure the snap ring is on the end of the shaft inside the housing but how do you get at it?

trigtm · Post by **trigtm** » 29 Jun 2012, 10:52

You positive it's the diff?

There is a bearing that can go bad on the VC which gives you that noise and also causes vibration in the rear. Instead of taking the axles out and making stubs, I'd remove the VC from the torque tube and then reinstall the tube empty (need it there to align the diff properly) and see if that shuts up the issue.

I had the same thing happen.

Post by **Jack Rock** » 29 Jun 2012, 15:42

Maybe, maybe not. Regardless, the axles are loose in the diff - they rock up and down a fair bit, the seals are gone and now I've cut the outer boot. I need to go ahead with the axle remove now but I'm not sure how to get into the housing where the snap ring resides.

Post by **Jack Rock** » 10 Jul 2012, 11:00

Ok, got this job done finally. Inside the CV housing is a circlip, not a snap ring. Therefore, it is removed by a quick, firm pull. I found this out by accident because when I removed the axle the second time around I grabbed the end of the shaft instead of the middle and yanked - the shaft came out of the CV joint instead of the differential. Lucky, I guess.

In the end, my car is fully and permanently FWD now and drives much much smoother and quieter - no vibration and no noise.

Post by **rmmagow** » 10 Jul 2012, 11:39

I'm curious about this work. What actually happens, pull the axle out of the diff and hub, remove all the things out of the outer CV, take the axle out of the CV then just put the remaining part, the stub with the ABS ring and put it back one and tighten the axle nut? Sort of like swapping the axle but just replacing the end at the wheel with all the axle parts out of the diff? The diff ends up basically just sitting there right, nothing turns, just the pumpkin remains doing nothing?